1. Field
Embodiments of this invention relate to the field of cryptography.
2. Background
Adoption of public key cryptography has been tremendously limited by the “key management problem” that is, the problem of allowing users to reliably identify the public keys of their intended communication partners. One approach used to address this problem is to construct a Public Key Infrastructure (PKI). This approach designates one or more trusted public keys known by the members of the PKI. The computer system that has the trusted public keys can sign digital certificates containing the public keys of users and devices in the PKI. This process authenticates the public keys of the PKI members.
The primary difficulty addressed by PKI is the problem of key management and distribution. That is, of deciding how to get authenticated copies of particular individuals' or devices' public keys to those individuals and devices that need to rely on these keys. A PKI is a system of well-known trusted public keys, possibly hierarchically organized. In PKI the owner of a trusted-key is usually termed a “Certification Authority”, or CA. Those trusted keys are used to authenticate the keys of other members (users and devices) in the PKI by signing the keys for the members, thus creating a “digital certificate”. Such a certificate typically uses this trusted signature to link a public key to information indicating who owns the key (an identity certificate), or what the key is allowed to be used for (an attribute certificate), or at very minimum, just that the bearer of the corresponding private key is a valid member of this particular PKI or other trust system.
Such a PKI simplifies the key management problem, as the number of keys that must be exchanged a priori goes from many down to the number of the trusted public keys. As long as the information contained in a member's certificate is sufficient to indicate to the verifier of that certificate that they are communicating with their intended party, the signature on that certificate is enough to let them know that the public key contained therein belongs to a trusted entity.
Unfortunately, creation and management of PKIs, as well as distribution of certificates, has turned out to be incredibly difficult and complex. Even establishment of small special-purpose PKIs to support the use of public key cryptography for one application within one organization is generally considered to be too expensive and difficult. One reason for this is that the available software is complicated, expensive, and requires deep knowledge of standards and cryptography to be configured to be effective. As a result, in spite of the fact that the use of public key cryptography can dramatically increase the security of many communications protocols (as compared, for example, to password-based alternatives), protocol designers are forced to move to less secure alternatives that do not require the “burden” of PKI establishment. Similarly, this cost of setting up a PKI keeps individuals from considering larger-scale use of public key cryptography in embedded devices (e.g. cell phones, printers, etc), as each of these devices would have to be “provisioned” with a certificate before use.
Furthermore, the key management and distribution problem described above in the PKI context exists with any secure credential infrastructure that has a credential issuing authority to issue credentials.
A derivative problem exists for wireless networks. These networks have proved notoriously difficult for even knowledgeable corporate IT departments to configure securely. This has led to many deployed networks exposing information and network resources to strangers thus, leaving client machines vulnerable to attack. While standards bodies have begun to specify technologies capable of securing these networks, these new security technologies are complex, and even more difficult to configure and manage than the existing technologies. In many environments (for example home, small business, or mobile wireless networks), it will be difficult, if not impossible, for network users to effectively configure and manage these networks to make them secure (many current wireless users find that 802.11b WEP is difficult to configure).
The standards body responsible for improving the security of the 802.11 standard are adapting the 802.1x standard for use on 802.11 networks.
In 802.1X's most secure configuration, clients and authentication servers authenticate each other and secure their communications using Transport Layer Security (TLS), which requires both the client and server to have a digital certificate with which they authenticate to each other. To distribute such certificates requires the deployment of a PKI (or other secure credential infrastructure) and the installation of a unique client certificate on each network client. This is a notoriously difficult task and subject to incorrect configurations that can leave clients vulnerable to rogue machines who can gain access to the shared wireless medium; those rogue machines can then use those vulnerable (but authenticated) clients as a base from which to attack the corporate LAN. Again, in situations where this approach is successful, it is either difficult to configure and manage, expensive, or totally out of the reach of small network users.
Another problem with ubiquitous computing environments within or around a vehicle or transportation infrastructure is that wireless communication of private data from a person's device to the vehicle or transportation infrastructure is difficult to establish securely. Another problem is that access to infrastructure and services is generally associated with the vehicle instead of the operator of the vehicle (for example, GM's OnStar™ system or automated toll payment systems).
It would be advantageous to use a secure credential infrastructure such as a PKI with the transportation infrastructure and private and public vehicles to provide secure wireless communication with the vehicle's components and to provide secure communications from the vehicle to associated infrastructure. It would also be advantageous to associate with an operator of the vehicle information and services that currently are associated with the vehicle itself.